Rollover Prevention Apparatus

ABSTRACT

The rollover prevention apparatus defines an adaptive steering range limiting device comprising a control unit and a pair of opposing unidirectional brake assemblies mounted to a steering column position detection disc. The rollover prevention apparatus prevents the steering wheel of the vehicle from being turned beyond the threshold of vehicle rollover, but otherwise does not restrict the rotational range of motion of the steering wheel of a vehicle.

CROSS REFERENCE TO RELATED APPLICATIONS

This nonprovisional utility patent application is a continuation of andclaims the benefit under 35 USC §120 to co-pending U.S. application Ser.No. 14/733,042 filed Jun. 8, 2015 and expected to issue as U.S. Pat. No.9,580,103 on Feb. 28, 2017, which is a continuation of and claims thebenefit under 35 USC §120 to co-pending U.S. application Ser. No.14/145,950 filed Jan. 1, 2014 and since issued as U.S. Pat. No.9,050,997 on Jun. 9, 2015, which is a continuation-in-part of and claimsthe benefit under 35 USC §120 to co-pending U.S. application Ser. No.13/222,157 filed Aug. 31, 2011 and since issued as U.S. Pat. No.8,634,989 on Jan. 21, 2014, which claims the benefit under 35 USC§119(e) of U.S. provisional application No. 61/378,482 filed Aug. 31,2010 and of U.S. provisional application No. 61/385,535 filed Sep. 22,2010, all of which are expressly incorporated herein in their entiretyby this reference.

FIELD OF THE INVENTION

The present invention relates to steering control devices and moreespecially devices for use in preventing steering to the point ofvehicle rollover.

BACKGROUND OF THE INVENTION

Vehicle rollover—generally defined as vehicular accident in which avehicle turns over on its side or roof—is an extremely dangerous form ofa vehicle crash. Vehicle rollover accidents while relativelyrare—estimated at approximately 3% of all vehicle crashes—account for adisproportionately high number of fatal crashes—estimated atapproximately 31% of all fatal vehicle crashes. The Nation HighwayTransportation Safety Administration (NHTSA) reported that 10,666 peoplewere killed in the US in vehicle rollover crashes in 2002. Many factorsare involved in a vehicle rollover including for instance vehicle centerof gravity, vehicle suspension stiffness, vehicle tire traction, etc.However, according to Wikipedia, “The main cause for rolling over isturning too sharply while moving too fast” (see Appendix A, page 1,first paragraph). While there may be several factors for a vehicle to beturned or steered beyond the vehicle threshold of roll such as driverhurry or impatience and driver inexperience, a well know cause forexcessive turning or steering to the point of vehicle roll is theoccurrence of an object such as a tumble weed or squirrel suddenlyappearing in the drivers path (hereafter referred to Sudden ObjectAppearance or SOA). In such SOA, even the most experienced drivers canfeel the inherent and immediate urge to rapidly turn the steering wheel.It is just such turning of the steering wheel that causes many vehiclerollovers.

In recent years, a system commonly referred to as Electronic StabilityControl or ESC has, by automatically selectively apply torque or brakingforce to certain of a vehicles wheels, been used in significantlyimproving stability of vehicles, especially when such vehicles wouldhave otherwise “spun out” or “fish-tailed” when cornering. However, suchESC systems, which typically require complex rollover predictionschemes, cannot prevent vehicle rollover when a vehicle steering wheelis turned too sharply for the vehicle speed as in a SOA situation.Further, a number of inventions dealing with vehicle steering controlhave been developed over the years. However, such inventions havetypically merely dealt with preventing damage to a driving surface (i.e.turf) or prevention of a power steering system, and no such systems areknown to prevent vehicle rollover, especially in a SOA situation.Examples of such inventions are provided in the following list of USpatents and applications, the whole of which are incorporated herein byreference: U.S. Pat. Nos. 5,489,006, 6,584,388, 6,588,799, 6,714,848,6,954,140, 7,107,136, 7,261,303, 7,325,644, 7,440,844, 7613,555,20030055549, 20030088349, 20030093201, 20040102894, 20040104066,20040215384, 20050060069, 20050110227, 20060030991, 20060129298,20060162987, 20070299583, 20080133101, 20090228173, 20100191423, and20110060505.

SUMMARY OF THE INVENTION

The present invention is a vehicle rollover prevention apparatus. Thusunless indicated otherwise, where used in this application, the term“Anti-Roll Steering” or “ARS” shall be understood to mean a system orapparatus that adaptively adjusts the steering range of motion of avehicle such as to prevent rollover of the vehicle. Thus for instance,ARS allows a vehicle steering to be steered in a full unrestricted rangeof motion when the vehicle is moving substantially below a predeterminedspeed (such as the speed that correlates to a roll threshold of thevehicle at a given turn angle or turn rate of the vehicle), but preventsa vehicle steering from being steered in a full unrestricted range ofmotion when the vehicle is moving at or near the predetermined speed. Ina first embodiment, the apparatus defines an adaptive steering rangelimiting device (ASRLD) comprising a control unit and a pair of opposingunidirectional brake assemblies mounted to a steering column positiondetection disc (SCPDD). The unidirectional brake assemblies comprise afirst left hand unidirectional brake assembly (LHUBA) and a second righthand unidirectional brake assembly (RHUBA), with the LHUBA operable tobrake in a left hand or counterclockwise (CCW) direction and yet rollsubstantially freely in a right hand or clockwise (CW) direction, andwith the RHUBA operable to brake in a right hand or clockwise (CW)direction and yet roll substantially freely in a left hand orcounterclockwise (CCW) direction. The SCPDD includes at least one andpreferably a plurality of sensors that sense the angular position of avehicle steering wheel and provide such angular position information tothe control unit. The control unit also receives speed data from avehicle speed sensor. In practice, when a vehicle in which the ASRLD isinstalled is moving at less than a predetermined rate of speed, theunidirectional brake assemblies are not applied, and the vehiclesteering wheel may be turned to the full hand range of steering motion.However, when a vehicle in which the ASRLD is installed is moving at noless than a predetermined rate of speed and the vehicle steering wheelis turned to no less than a predetermined left hand angle, the LHUBA isautomatically applied, and the vehicle steering left hand range ofmotion is restricted such that the steering wheel may not be turnedbeyond the threshold of left hand rollover for the particular vehiclefor the given vehicle speed. When the vehicle speed and/or steeringwheel left hand angle is reduced, the LHUBA is automatically released.Further, when a vehicle in which the ASRLD is installed is moving at noless than a predetermined rate of speed and the vehicle steering wheelis turned to no less than a predetermined right hand angle, the RHUBA isautomatically applied, and the vehicle steering right hand range ofmotion is restricted such that the steering wheel may not be turnedbeyond the threshold of right hand rollover for the particular vehiclefor the given vehicle speed. When the vehicle speed and/or steeringwheel right hand angle is reduced, the RHUBA is automatically released.It is noted that when the unidirectional brake assemblies are(separately) applied, although the steering wheel is prevented frombeing turn beyond a predetermined left hand or right hand angle, thesteering wheel is free to be turned back toward a steering wheelcentered or neutral position. In this method, a vehicle is preventedfrom being steered beyond the threshold of vehicle role and yet thevehicle steering wheel remains otherwise usable over the unrestrainedrotational range of travel.

DESCRIPTION OF DRAWINGS

In order that the advantages of the invention will be readilyunderstood, a more particular description of the invention brieflydescribed above will be rendered by reference to specific embodimentsthat are illustrated in the appended drawings. Understanding that thesedrawings depict only typical embodiments of the invention and are nottherefore to be considered to be limiting of its scope, the inventionwill be described and explained with additional specificity and detailthrough the use of the accompanying drawings, in which:

FIG. 1 is a trimetric view of a first embodiment of the invention;

FIG. 2 is an orthographic cross-sectional view of the first embodimentof the invention taken substantially at the location indicated by thecross-section arrows annotated with “2” in FIG. 1;

FIG. 3A is an orthographic cross-sectional view of the first embodimentof the invention taken substantially at the location indicated by thecross-section arrows annotated with “3” in FIG. 2, the invention isshown with the LHUBA in an unactuated or open position;

FIG. 3B is an orthographic cross-sectional view of the first embodimentof the invention taken substantially at the location indicated by thecross-section arrows annotated with “3” in FIG. 2, the invention isshown with the LHUBA in an actuated or closed position;

FIG. 4A is an orthographic cross-sectional view of the first embodimentof the invention taken substantially at the location indicated by thecross-section arrows annotated with “4” in FIG. 2, the invention isshown with the RHUBA in an unactuated or open position;

FIG. 4B is an orthographic cross-sectional view of the first embodimentof the invention taken substantially at the location indicated by thecross-section arrows annotated with “4” in FIG. 2, the invention isshown with the RHUBA in an actuated or closed position;

FIG. 5 is a trimetric view of a fourth embodiment of the invention;

FIG. 6A is an orthographic cross-sectional view of the fourth embodimentof the invention taken substantially at the location indicated by thecross-section arrows annotated with “6” in FIG. 5;

FIG. 6B is substantially similar to FIG. 6A except that a first set ofactuator pins are shown as extended;

FIG. 6C is substantially similar to FIG. 6A except that a second set ofactuator pins are shown as extended;

FIG. 6D is substantially similar to FIG. 6A except that a third set ofactuator pins are shown as extended;

FIG. 6E is substantially similar to FIG. 6D except that SCDD 140 isshown rotated to the limit of its right hand rotational range of motion;

FIG. 7 is an orthographic cross-sectional view of the fourth embodimentof the invention taken substantially at the location indicated by thecross-section arrows annotated with “7” in FIG. 6D, with the inventionshown without an actuation pin 144 blocking rotational motion of SCDD140, and;

FIG. 7A is an orthographic cross-sectional view of the fourth embodimentof the invention taken substantially at the location indicated by thecross-section arrows annotated with “7” in FIG. 6E, with the inventionshown with an actuation pin 144 a blocking rotational motion of SCDD140.

DETAILED DESCRIPTION OF THE INVENTION

Reference throughout this specification to “one embodiment,” “anembodiment,” or similar language means that a particular feature,structure, or characteristic described in connection with the embodimentis included in at least one embodiment of the present invention. Thus,appearances of the phrases “in one embodiment,” “in an embodiment,” andsimilar language throughout this specification may, but do notnecessarily, all refer to the same embodiment.

Furthermore, the described features, structures, or characteristics ofthe invention may be combined in any suitable manner in one or moreembodiments. In the following description, numerous specific details areincluded to provide a thorough understanding of embodiments of theinvention. One skilled in the relevant art will recognize, however, thatthe invention can be practiced without one or more of the specificdetails, or with other methods, components, materials, and so forth. Inother instances, well-known structures, materials, or operations are notshown or described in detail to avoid obscuring aspects of theinvention.

In order to facilitate the understanding of the present invention inreviewing the drawings accompanying the specification, a feature tableis provided below. It is noted that like features are like numberedthroughout all of the figures.

FEATURE TABLE # Feature 10 adaptive steering range limiting device 20steering wheel 30 steering column 40 steering column position detectiondisc 42 disc 44 magnetic target 50 unidirectional brake assemblies 60left hand unidirectional brake assembly 62 caliper housing 64unidirectional roller 70 right hand unidirectional brake assembly 72caliper housing 74 unidirectional roller 80 electronic control unit 85sensor 92 left hand or CCW direction indication arrow 94 right hand orCW direction indication arrow 110  adaptive steering range limitingdevice 120  steering wheel 130  steering column 140  steering columndisc device 142  disc 144  actuator pin 144a actuator pin - extended180  electronic control unit 185  block 192  left hand or CCW directionindication arrow 194  right hand or CW direction indication arrow

Referring now to FIGS. 1 through 4 of the drawings, a first embodimentof the invention is an adaptive steering range limiting device (ASRLD)10 comprising a steering wheel 20, a steering column 30, a steeringcolumn position detection disc (SCPDD) 40, a pair of opposingunidirectional brake assemblies 50, an electronic control unit 80 and asensor 85. Furthermore arrow 92 defines a left hand or counterclockwise(CCW) direction indication arrow and arrow 94 defines a right hand orclockwise (CW) direction indication arrow. Steering wheel 20 defines aconventional steering wheel as may commonly be found in a commerciallyavailable passenger vehicle. Steering column 30 defines a conventionalsteering column that serves to transmit steering torque from steeringwheel 20 to a rack and pinion or other such vehicle wheel controldevice. SCPDD 40 defines a substantially thin preferably aluminumcylinder shaped disc 42 having a plurality of magnetic targets 44embedded within disc 42 and spaced substantially equally about theperiphery of disc 42. Unidirectional brake assemblies 50 define anassembly comprising a left hand unidirectional brake assembly (LHUBA) 60and a right hand unidirectional brake assembly (RHUBA) 70. LHUBA 60defines a brake assembly having a caliper housing 62, and a plurality ofactuatable or extendable and retractable unidirectional rollers 64.Unidirectional roller 64 preferably comprises a generally hard rubberroller mounted on at least one unidirectional bearing. Unidirectionalbearings are well known in the art and are for instance taught in U.S.Pat. Nos. 3,805,932 and 5,547,055, which are incorporated herein byreference. RHUBA 70 defines a brake assembly having a caliper housing72, and a plurality of actuatable or extendable and retractableunidirectional rollers 74. Unidirectional roller 74 preferably comprisesa generally hard rubber roller mounted on at least one unidirectionalbearing. Electronic control unit 80 defines an electronic control unitsuch as are commonly in use in automobiles, and is adapted toelectronically receive speed, position and other sensor input and isadapted to electronically transmit actuation signals based onpredetermined inputs. Sensor 85 preferably defines an electronic sensorsuch as reed switch type sensor that is operable to detect nearproximity to magnetic targets 44, and thus is operable to detectrotational positioning of SCPDD 40.

ASRLD 10 is assembled such that steering column 30 is connected tosteering wheel 20 on a first end of steering column 30 and to SCPDD 40on a second end of steering column 30. Unidirectional brake assemblies50 are positioned near SCPDD 40 such that disc 42 may rotatingly passbetween rollers 64 and between rollers 74. Electronic control unit 80 iselectronically connected to unidirectional brake assemblies 50 andelectronically connected to sensor 85. ASRLD 10 is mounted in a vehiclesuch that second end of steering column 30 is steeringly connected to arack and pinion or like steering mechanism of the vehicle such thatASRLD 10 is operable to steer the vehicle. Unidirectional brakeassemblies 50 are further connected to a structural member of thevehicle such that unidirectional brake assemblies 50 remain stationaryrelative to a rotation movement of SCPDD 40 and such that unidirectionalbrake assemblies 50 are able to react or withstand a steering stoppingload. Electronic control unit 80 is further connected to a structuralmember of the vehicle such that electronic control unit 80 remainsstationary regardless of rotation movement of SCPDD 40. Sensor 85 isfurther connected to a structural member of the vehicle such that sensor85 remains stationary relative to a rotation movement of SCPDD 40 andsuch that sensor 85 is able to detect magnetic targets 44 as magnetictargets 44 move into a near proximity position to sensor 85.

In practice, with ASRLD 10 operably mounted in a vehicle, when thevehicle is moving below a predetermined speed, for instance less than 10miles per hour (mph), unidirectional brake assemblies 50 are notactuated as shown in FIGS. 3A and 4A, and steering wheel 20 may befreely rotated through its the full rotational range of motion. It isnoted that when steering wheel 20 is rotated, SCPDD 40 correspondinglyrotates between rollers 64 and between rollers 74 and sensor 85 andelectronic control unit 80 monitors the rotational orientation of SCPDD40. However, when the vehicle is moving at or above a predeterminedspeed, for instance 10 miles per hour (mph), and SCPDD 40 is sensed atbeing at or above a left hand rotational orientation of greater than apredetermined amount, for instance 10 degrees CCW from a center orneutral steering position, electronic control unit 80 determines asteering prevention threshold has been achieved and sends an actuationsignal to LHUBA 60, and LHUBA 60 actuates by moving unidirectionalrollers 64 into unidirectional braking contact with SCPDD 40 as shown inFIG. 3B and steering wheel 20 is prevented from rotating further in aleft hand or CCW direction but is free to rotate in a right hand or CWdirection. When the vehicle slows to less than the predetermined speedor when steering wheel 20 is rotated to a rotational orientation ofbelow the predetermined amount, LHUBA 60 “deactuates” by movingunidirectional rollers 64 out of braking contact with SCPDD 40 as shownin FIG. 3A, and steering wheel 20 may again be rotated freely in bothdirections (CCW and CW) unless and until another steering preventionthreshold is reached. Further, when the vehicle is moving at or above apredetermined speed, for instance 10 miles per hour (mph), and SCPDD 40is sensed at being at or above a right hand rotational orientation ofgreater than a predetermined amount, for instance 10 degrees CW from acenter or neutral steering position, electronic control unit 80determines a steering prevention threshold has been achieved and sendsan actuation signal to RHUBA 70, and RHUBA 70 actuates by movingunidirectional rollers 74 into unidirectional braking contact with SCPDD40 as shown in FIG. 4B and steering wheel 20 is prevented from rotatingfurther in a right hand or CW direction but is free to rotate in a lefthand or CCW direction. When the vehicle slows to less than thepredetermined speed or when steering wheel 20 is rotated to a rotationalorientation of below the predetermined amount, RHUBA 70 “deactuates” bymoving unidirectional rollers 74 out of braking contact with SCPDD 40 asshown in FIG. 4A, and steering wheel 20 may again be rotated freely inboth directions (CCW and CW) unless and until another steeringprevention threshold is reached.

It is noted that ASRLD 10 is preferably adapted such that the varioussteering prevention thresholds are of substantially fine increments suchthat the braking of steering wheel 20 is accomplished in a fashion thatapproximates a smooth non-stair-stepped method. For example, if avehicle equipped with ASRLD 10 were to be traveling on a substantiallylarge flat horizontal paved surface at a high rate of speed, such as forinstance 100 mph, and steering wheel 20 were to be turned hard to theright (or the left), ASRLD 10 would prevent steering wheel 20 from beingturned to the right (or the left) to the point that the vehicle wouldrollover to the left (or to the right), and would more specifically,allow steering wheel 20 to be turned to the right (or the left) verynear to but just less than the threshold of vehicle rollover. Further,in the above described scenario, if the right hand (or left hand)steering load were maintained on steering wheel 20 and the vehicle wasto be allowed to decelerate, such as by coasting or by braking, thevehicle would turn to the right (or to the left) at an substantiallycontinuously sharper right hand (or left hand) turn (e.g. asubstantially decreasing turn radius) corresponding to the decreasedrate of speed until the vehicle slowed to the point that it would betraveling at less than the first or slowest steering preventionthreshold (such as less than 10 mph). Once the vehicle slowed to thefirst or slowest steering prevention threshold, the vehicle would thenturn to the right (or to the left) at a constant turn rate which wouldbe the full unrestricted turn rate of the vehicle. Thus by thisdescription, it can be seen that at substantially any speed of thevehicle, the vehicle is allowed to turn at a rate approaching but justless than the vehicle rollover threshold for such given “any” speed.ASRLD 10 is somewhat analogous to “anti-lock braking”. With anti-lockbraking, braking and vehicle control is maximized (breaking distanceminimized) by allowing the brakes to apply a braking force thatapproaches but is never allowed to exceed the tire-to-ground tractionbreaking threshold. Analogously, with ASRLD 10, steering and vehiclecontrol is maximized by allowing the vehicle to be steered to a degreethat approaches but is never allowed to exceed the vehicle rolloverthreshold.

It is noted that each vehicle model or alteration thereof may have adifferent propensity for roll. In the first embodiment, such propensityis predetermined and corresponding combinations of turn degree andvehicle speed are determined for various vehicle rollover thresholds.However, it is also understood that vehicle roll propensity isinfluenced a plurality of factors. In addition to speed and turn degree,such factors may include for instance vehicle center of gravity, vehiclesuspension stiffness, vehicle wheel base width, vehicle loading, vehicletire pressure, traction between a road and the vehicle tires, roadangle/banking, etc. Thus in a second embodiment, the second embodimentis substantially identical to the first embodiment except that in thesecond embodiment, factors in addition to vehicle speed and turn degreeare monitored and rollover thresholds are determined on-the-fly. Furtherin the second embodiment, in order to prevent vehicle rollover due tocontinued or increased acceleration post-actuation of ASRLD 10,electronic control unit 80 is adapted such that whenever ASRLD 10 isactuated, electronic control unit 80 sends a signal to an acceleratorcontrol device such that a vehicle is prevented from furtheracceleration during the duration of ASRLD 10 actuation.

It is noted that inasmuch as there may be a belief by some that certaincircumstances may exist wherein the likelihood of injury or death may beless if a vehicle is allowed to be steered beyond a vehicle threshold ofrollover than if a vehicle is restricted from being steered beyond avehicle threshold of rollover. To satisfy such potential concerns, in athird embodiment, the third embodiment is substantially identical to thesecond embodiment except that the third embodiment includes an overridemode. In such override mode the steering rotational range of motion isautomatically not restricted even if a steering prevention threshold isexceeded if an override logic criterion is satisfied. Such overridelogic criteria may comprise for instance, the detection of a human innear proximity of the drive path of the vehicle or for instance, thedetection of a road surface having less than a predetermined coefficientof friction (e.g. an ice packed road).

Referring now to FIGS. 5 through 7 of the drawings, a fourth embodimentof the invention is an adaptive steering range limiting device (ASRLD)110 comprising a steering wheel 120, a steering column 130, a steeringcolumn disc device (SCDD) 140, an electronic control unit 180 and ablock 185. Furthermore arrow 192 defines a left hand or counterclockwise(CCW) direction indication arrow and arrow 194 defines a right hand orclockwise (CW) direction indication arrow. Steering wheel 120 defines aconventional steering wheel as may commonly be found in a commerciallyavailable passenger vehicle. Steering column 130 defines a conventionalsteering column that serves to transmit steering torque from steeringwheel 120 to a rack and pinion or other such vehicle wheel controldevice. SCDD 140 defines a substantially thin preferably aluminumcylinder shaped disc 142 having a plurality of actuator pins 144 affixedto disc 142 and spaced substantially equally about the periphery of disc142. Actuator pins 144 are mounted to disc 142 such that in anun-actuated or retracted position, actuator pins 144 are positionedsubstantially flush with disc 142 and such that in an actuated orextended position, actuator pins 144 are positioned substantially in aposition so as to potentially interfere with block 185. Electroniccontrol unit 80 defines an electronic control unit such as are commonlyin use in automobiles, and is adapted to electronically receive speedinput and is adapted to electronically transmit actuation signals basedon predetermined inputs. Block 185 preferably defines rigidly fixedpreferably metallic block that is connect to a vehicle structural memberand does not move with disc 142.

ASRLD 110 is assembled such that steering column 130 is connected tosteering wheel 120 on a first end of steering column 130 and to SCDD 140on a second end of steering column 130. Electronic control unit 180 iselectronically connected to actuator pins 144. ASRLD 110 is mounted in avehicle such that second end of steering column 130 is steeringlyconnected to a rack and pinion or like steering mechanism of the vehiclesuch that ASRLD 110 is operable to steer the vehicle. Block 185 isconnected to a structural member of the vehicle such that block 185remains stationary relative to a rotation movement of SCDD 140 and suchthat block 185 is able to react or withstand a steering stopping load.Electronic control unit 180 is further connected to a structural memberof the vehicle such that electronic control unit 180 remains stationaryregardless of rotation movement of SCDD 140.

In practice, with ASRLD 110 operably mounted in a vehicle, when thevehicle is moving below a predetermined speed, for instance less than 5miles per hour (mph), none of actuator pins 144 are actuated as shown inFIGS. 6A and 6, and steering wheel 120 may be freely rotated through itsthe full (unrestricted) rotational range of motion. It is noted thatwhen steering wheel 120 is rotated, SCDD 140 correspondingly in verynear proximity to stationary block 185. However, when the vehicle ismoving at or above a first predetermined speed, for instance 10 milesper hour (mph), electronic control unit 80 determines a first steeringprevention threshold has been achieved and sends an actuation signal toa first set of actuator pins 144 as shown in FIG. 6B and steering wheel120 is prevented from rotating beyond a first restricted range ofrotational motion. When the vehicle is moving at or above a secondpredetermined speed, for instance 35 miles per hour (mph), electroniccontrol unit 80 determines a second steering prevention threshold hasbeen achieved and sends an actuation signal to a second set of actuatorpins 144 as shown in FIG. 6C and steering wheel 120 is prevented fromrotating beyond a second restricted range of rotational motion. When thevehicle is moving at or above a third predetermined speed, for instance65 miles per hour (mph), electronic control unit 80 determines a thirdsteering prevention threshold has been achieved and sends an actuationsignal to a third set of actuator pins 144 as shown in FIG. 6D andsteering wheel 120 is prevented from rotating beyond a third restrictedrange of rotational motion. When the vehicle slows to less than a givenpredetermined speed threshold, or when a more restrictive set ofactuator pins 144 are actuated or extended, electronic control unit 80sends an retraction signal to a given set of actuator pins 144, andactuator pins 144 “deactuate” or retract and return to their homeposition, steering wheel 120 may again be rotated freely in bothdirections (CCW and CW) unless and until another steering preventionthreshold is reached. It is noted that in the fourth embodiment of theinvention, in contrast to systems that react to initiation of vehiclerollover. ASRLD 110 functions in a “proactive” mode by preventing thevehicle from initiating a rollover.

It is noted that ASRLD 110 is preferably adapted such that the varioussteering prevention thresholds are of substantially fine increments suchthat the varying of steering range of motion of steering wheel 120 isaccomplished in a fashion that approximates a smooth non-stair-steppedmethod. For example, if a vehicle equipped with ASRLD 110 were to betraveling on a substantially large flat horizontal paved surface at ahigh rate of speed, such as for instance 100 mph, and steering wheel 120were to be turned hard to the right (or the left), ASRLD 110 wouldprevent steering wheel 120 from being turned to the right (or the left)to the point that the vehicle would rollover to the left (or to theright), and would more specifically, allow steering wheel 120 to beturned to the right (or the left) very near to but just less than thethreshold of vehicle rollover. Further, in the above described scenario,if the right hand (or left hand) steering load were maintained onsteering wheel 120 and the vehicle was to be allowed to decelerate, suchas by coasting or by braking, the vehicle would turn to the right (or tothe left) at an substantially continuously sharper right hand (or lefthand) turn (e.g. a substantially decreasing turn radius) correspondingto the decreased rate of speed until the vehicle slowed to the pointthat it would be traveling at less than the first or slowest steeringprevention threshold (such as less than 10 mph). Once the vehicle slowedto the first or slowest steering prevention threshold, the vehicle wouldthen turn to the right (or to the left) at a constant turn rate whichwould be the full unrestricted turn rate of the vehicle. Thus by thisdescription, it can be seen that at substantially any speed of thevehicle, the vehicle is allowed to turn at a rate approaching but justless than the vehicle rollover threshold for such given “any” speed.ASRLD 110 is somewhat analogous to “anti-lock braking”. With anti-lockbraking, braking and vehicle control is maximized (breaking distanceminimized) by allowing the brakes to apply a braking force thatapproaches but is never allowed to exceed the tire-to-ground tractionbreaking threshold. Analogously, with ASRLD 110, steering and vehiclecontrol is maximized by allowing the vehicle to be steered to a degreethat approaches but is never allowed to exceed the vehicle rolloverthreshold.

What is claimed is:
 1. A steering apparatus having a steering inputdevice, an actuator, at least one sensor, and an electronic controlunit, wherein said steering input device is adapted such that an inputto said steering input device causes a corresponding change to a turnangle of a vehicle, and wherein said actuator is operatively adapted toactuate upon receipt of an actuation signal, and wherein said sensor isadapted to sense the magnitude of at least one driving parameter, andwherein said electronic control unit is adapted to send an actuationsignal to said actuator when a sensed driving parameter exceeds apredetermined magnitude, and wherein said steering apparatus is adaptedto allow a vehicle to be steered within a non-rollover steering range ofmotion of said vehicle but said steering apparatus is adapted to preventsaid vehicle from being steered beyond a rollover threshold of saidvehicle.
 2. The apparatus of claim 1, wherein said steering input devicedefines a steering wheel.
 3. The apparatus of claim 1, wherein said atleast one driving parameter defines at least one of vehicle speed,degree of steering turn, vehicle center of gravity, vehicle suspensionstiffness, vehicle wheel base width, vehicle loading, vehicle tirepressure, traction between a road and vehicle tires, and road bankangle.
 4. The apparatus of claim 1, wherein said actuation signal issent by said electronic control unit when the combination of sensedvehicle speed and degree of steering turn approach a rollover thresholdof said vehicle.
 5. The apparatus of claim 1, wherein said apparatus hasa first mode and a second mode, and wherein when said apparatus is insaid first mode, said apparatus allows a vehicle to be steered within anon-rollover steering range of motion of said vehicle, wherein when saidapparatus is in said second mode, said apparatus automatically preventssaid vehicle from being steered beyond a rollover threshold of saidvehicle, and wherein said apparatus automatically performs at least oneof a transition from said first mode to said second mode and atransition from said second mode to said first mode.
 6. The apparatus ofclaim 1, wherein said apparatus has a first mode and a second mode, andwherein when said apparatus is in said first mode, said apparatus allowsa vehicle to be steered within a non-rollover steering range of motionof said vehicle, wherein when said apparatus is in said second mode,said apparatus automatically prevents said vehicle from being steeredbeyond a rollover threshold of said vehicle, and wherein said apparatustransitions from said second mode to said first mode in response toapplication of load to a steering wheel.
 7. The apparatus of claim 6,wherein said application of load to a steering wheel further definesapplication of load to a steering wheel such that said steering wheel isrotated to a rotational orientation of below a steering preventionthreshold.
 8. A steering apparatus having a steering input device, anactuator, at least one sensor, and an electronic control unit, whereinsaid steering input device is adapted such that an input to saidsteering input device causes a corresponding change to a turn angle of avehicle, and wherein said actuator is operatively adapted to actuateupon receipt of an actuation signal, and wherein said sensor is adaptedto sense the magnitude of at least one driving parameter, and whereinsaid electronic control unit is adapted to send an actuation signal tosaid actuator when a sensed driving parameter exceeds a predeterminedmagnitude, and wherein said steering apparatus is adapted to allow avehicle to be steered within a non-rollover steering range of motion ofsaid vehicle but said steering apparatus is adapted to prevent saidvehicle from being steered such that said vehicle would roll over whenrounding a curve of such a magnitude and at such a speed that saidvehicle would roll over if the turn angle of said vehicle were to exceeda rollover threshold of said vehicle.
 9. The apparatus of claim 8,wherein said steering input device defines a steering wheel.
 10. Theapparatus of claim 8, wherein said at least one driving parameterdefines at least one of vehicle speed, degree of steering turn, vehiclecenter of gravity, vehicle suspension stiffness, vehicle wheel basewidth, vehicle loading, vehicle tire pressure, traction between a roadand vehicle tires, and road bank angle.
 11. The apparatus of claim 8,wherein said actuation signal is sent by said electronic control unitwhen the combination of sensed vehicle speed and degree of steering turnapproach a rollover threshold of said vehicle.
 12. The apparatus ofclaim 8, wherein said apparatus has a first mode and a second mode, andwherein when said apparatus is in said first mode, said apparatus allowsa vehicle to be steered within a non-rollover steering range of motionof said vehicle, wherein when said apparatus is in said second mode,said apparatus automatically prevents said vehicle from being steeredbeyond a rollover threshold of said vehicle, and wherein said apparatusautomatically performs at least one of a transition from said first modeto said second mode and a transition from said second mode to said firstmode.
 13. The apparatus of claim 8, wherein said apparatus has a firstmode and a second mode, and wherein when said apparatus is in said firstmode, said apparatus allows a vehicle to be steered within anon-rollover steering range of motion of said vehicle, wherein when saidapparatus is in said second mode, said apparatus automatically preventssaid vehicle from being steered beyond a rollover threshold of saidvehicle, and wherein said apparatus transitions from said second mode tosaid first mode in response to application of load to a steering wheel.14. The apparatus of claim 13, wherein said application of load to asteering wheel further defines application of load to a steering wheelsuch that said steering wheel is rotated to a rotational orientation ofbelow a steering prevention threshold.
 15. A vehicle having steeringapparatus comprising a steering wheel, an actuator, at least one sensor,and an electronic control unit, wherein said steering wheel is adaptedsuch that an input to said steering wheel causes a corresponding changeto a turn angle of said vehicle, and wherein said actuator isoperatively adapted to actuate upon receipt of an actuation signal, andwherein said sensor is adapted to sense the magnitude of at least onedriving parameter, and wherein said electronic control unit is adaptedto send an actuation signal to said actuator when a sensed drivingparameter exceeds a predetermined magnitude, and wherein said vehicle isadapted to be steerable within a non-rollover steering range of motionof said vehicle but said steering apparatus is adapted to prevent saidsteering wheel from being rotated to the point that said vehicle wouldroll over when rounding a curve of such a magnitude and at such a speedthat said vehicle would roll over if said steering wheel were rotatedbeyond said point.
 16. The vehicle of claim 15, wherein said at leastone driving parameter defines at least one of vehicle speed, degree ofsteering turn, vehicle center of gravity, vehicle suspension stiffness,vehicle wheel base width, vehicle loading, vehicle tire pressure,traction between a road and vehicle tires, and road bank angle.
 17. Thevehicle of claim 15, wherein said actuation signal is sent by saidelectronic control unit when the combination of sensed vehicle speed anddegree of steering turn approach a rollover threshold of said vehicle.18. The vehicle of claim 15, wherein said apparatus has a first mode anda second mode, and wherein when said apparatus is in said first mode,said apparatus allows said vehicle to be steered within a non-rolloversteering range of motion of said vehicle, wherein when said apparatus isin said second mode, said apparatus automatically prevents said vehiclefrom being steered beyond a rollover threshold of said vehicle, andwherein said apparatus automatically performs at least one of atransition from said first mode to said second mode and a transitionfrom said second mode to said first mode.
 19. The vehicle of claim 15,wherein said apparatus has a first mode and a second mode, and whereinwhen said apparatus is in said first mode, said apparatus allows saidvehicle to be steered within a non-rollover steering range of motion ofsaid vehicle, wherein when said apparatus is in said second mode, saidapparatus automatically prevents said vehicle from being steered beyonda rollover threshold of said vehicle, and wherein said apparatustransitions from said second mode to said first mode in response toapplication of load to said steering wheel.
 20. The vehicle of claim 19,wherein said application of load to said steering wheel further definesapplication of load to said steering wheel such that said steering wheelis rotated to a rotational orientation of less than said point.